Season 1 Episode 8:

Urban Chipmunk; Incredible Shrinking Dave

Season 1 Episode 7:

The Chip Punks; From Here to Fraternity

Alvin decides to change the Chipmunks' clean-cut image to a punkier, more rebellious one in order to gain more publicity; the Chipmunks start a singing telegraph service to help buy some golf clubs for Dave's birthday.